Honestly I didn't vote because it all depends.

With Huney and Roxey it's usually 2-3x's/yr. They get their bath at the groomers unless they happened to get into something very stinky and then and only then do I bath them. I keep them brushed on a regular basis so I'm sure that helps.
Now Bon on the other hand hasn't had a bath since last March when Amy and Kay were here But seriously he really doesn't need it. He goes out in the rain and gets soaked and when he comes in the house I towel him (and the girls) off. Guess that's what keeps him from being stinky and dirty.
It's like they get a bath every time it rains

Oh and I do have the Lambert and Kay Oatmeal Shampoo and Conditioner that we use when/if we have to.